Chhandogya Upanishad - 'Sarvam Khalu Idam Brahma' (All things here are Brahman), 'Tat twam asi' (You are that), 'Ekam evadvitiyam brahma' - (Brahman is one, without a second), Brihadaranyaka Upanishad - 'Aham Brahmasmi' (I am Brahman).....
Of course. But 'prajnanam brahman' is also from Chandogya. Brahman is 'satyam jnanam anantam'. Brahman is 'sat chit ananda'.
Purusha is intelligence that controls Prakriti. Kaivalya is Purusha un-entangling from Prakriti completely.
Ignoring the jnana part makes all these astika darsana same as Lokyata/Charvaka darsana.
Lokyayata/Charvaka are not part of Hinduism.